Voltage regulators and DC to DC converters are typically required to provide stable, regulated supply voltages for proper operation of processors, ASICS, memory, and other components in modern electronic circuits. Computers, smart phones, tablets, and other electronic products in particular require highly accurate supply voltages for operation of processors and other internal circuitry. DC to DC converter controllers typically provide closed loop converter operation to maintain a generally constant output voltage during initial power up, load transients, overcurrent conditions, and steady state operation. Switching converters typically include one or more switching devices operated by pulse width modulated switching control signals, and a common form of pulse width modulation (PWM) employs a generally fixed switching frequency with the controller modifying the width or duration of the switching control signal pulses to regulate the output voltage according to a feedback signal. Fixed frequency DC to DC conversion, however, suffers from voltage regulation limitations in the presence of abrupt changes in load current. Even in steady state operation, supply voltage accuracy is adversely impacted by offsets in the PWM comparator circuitry, current signal variation and reference divider errors, and analog integrator circuits are often employed to compensate system offsets. However, analog integrators require an external capacitor and occupy large amounts of integrated circuit die, and also suffer from high power consumption and finite time constants, leading to poor output regulation during load transients. Moreover, turning off analog integrators during transitions between discontinuous conduction mode (DCM) and continuous conduction mode (CCM) leads to instability as integration values stored as voltages across integrator capacitors discharge over time. Thus, analog integrator solutions require sacrifice of load efficiency by shutdown of analog integrators in light load condition, or may provide acceptable light-load efficiency and accuracy by reducing power from other functional block in the system. Digital integrators occupy less area and use less power than analog integrators, but digital integrators using a digital up/down counter suffer from loop stability problems, particularly for load transient conditions. Accordingly, a need remains for improved pulse width modulation controllers and DC to DC converters for improved regulation accuracy with better loop stability than traditional approaches.